powerpc: Remove duplicate definition for ppc_msgsnd_sync()

Remove duplicate definition of ppc_msgsnd_sync() introduced in commit
b87ac02 ("powerpc: Introduce msgsnd/doorbell barrier primitives").

No functional change intended.

Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <riteshh@linux.ibm.com>
[maddy: Updated commit message to fixed checkpatch.pl warning]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250813122319.62278-1-gautam@linux.ibm.com

Author: Gautam Menghani

arch/powerpc/include/asm/dbell.h

@@ -40,12 +40,6 @@ static inline void _ppc_msgsnd(u32 msg)
 				: : "i" (CPU_FTR_HVMODE), "r" (msg));
 }
 
-/* sync before sending message */
-static inline void ppc_msgsnd_sync(void)
-{
-	__asm__ __volatile__ ("sync" : : : "memory");
-}
-
 /* sync after taking message interrupt */
 static inline void ppc_msgsync(void)
 {
@@ -76,12 +70,6 @@ static inline void _ppc_msgsnd(u32 msg)
 	__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
 }
 
-/* sync before sending message */
-static inline void ppc_msgsnd_sync(void)
-{
-	__asm__ __volatile__ ("sync" : : : "memory");
-}
-
 /* sync after taking message interrupt */
 static inline void ppc_msgsync(void)
 {
@@ -91,6 +79,12 @@ static inline void ppc_msgsync(void)
 
 extern void doorbell_exception(struct pt_regs *regs);
 
+/* sync before sending message */
+static inline void ppc_msgsnd_sync(void)
+{
+	__asm__ __volatile__ ("sync" : : : "memory");
+}
+
 static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
 {
 	u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |